In surveying and construction, the laser level is affixed to a tripod, leveled and then spun to illuminate a horizontal plane. The laser beam projector employs a rotating head with a mirror for sweeping the laser beam about a vertical axis. If the mirror is not self-leveling, it is provided with visually readable level vials and manually adjustable screws for orienting the projector. A staff carried by the operator is equipped with a movable sensor, which can detect the laser beam and gives a signal when the sensor is in line with the beam (usually an audible beep). The position of the sensor on the graduated staff allows comparison of elevations between different points on the terrain.
A tower-mounted laser level is used in combination with a sensor on a wheel tractor-scraper in the process of land laser leveling to bring land (for example, an agricultural field) to near-flatness with a slight grade for drainage. The laser line level was invented by Steve Orosz. This type of level does not require a heavy motor to create the illusion of a line from a dot, rather, it uses a lens to transform the dot into a line.
Famous quotes containing the word level:
“Preschoolers sound much brighter and more knowledgeable than they really are, which is why so many parents and grandparents are so sure their progeny are gifted and super-bright. Because children’s questions sound so mature and sophisticated, we are tempted to answer them at a level of abstraction far beyond the child’s level of comprehension. That is a temptation we should resist.”
—David Elkind (20th century)